Exemplary embodiments of the present invention relate to a method for optimizing a power requirement of a motor vehicle, and a device for carrying out the method for optimizing the power requirement.
Known predictive temperature control systems for motor vehicles allow implementation of a predictive control strategy for controlling the temperature of the drive unit of the motor vehicle.
In the methods of the prior art, a future heat input, in particular of an internal combustion engine, is predictively computed with the aid of digital maps and position location of the motor vehicle, which may be carried out in particular by means of Global Positioning System (GPS) position finding, and early control intervention is performed in order to reduce the energy consumption and/or fuel consumption of the motor vehicle.
U.S. Patent document US 2007/0261648 A1 discloses a method for operating a temperature control system in which a future heat input is estimated from the expected route of the motor vehicle. In particular, an elevation profile of the expected route is taken into account, so that an additional high heat input occurring during uphill travel or a low heat input during downhill travel may be determined in advance. The temperature control system may thus be coordinated with the elevation profile. In particular, a high temperature may be temporarily accepted when, for example, extended downhill travel lies ahead. Unnecessary control interventions for regulating the temperature are thus avoided, thereby reducing the energy consumption and fuel consumption.
Exemplary embodiments of the present invention provide a method for optimizing a power requirement of a motor vehicle which is improved over the prior art.
In a method for optimizing a power requirement of a motor vehicle, which includes a speed control system for a drive unit and a temperature control system for a cooling circuit of the drive unit, a first power requirement of the drive unit to be expected and a second power requirement of the cooling circuit to be expected are determined based on at least one route parameter. According to the invention, a driving strategy corresponding to the route parameter is initially selected, and the first power requirement corresponding to the driving strategy and the second power requirement corresponding to the driving strategy are determined. Based on the determined first and second power requirements, the driving strategy is then adjusted in such a way that an overall power requirement of the motor vehicle is minimized.
The first power requirement that is to be expected for a selected driving strategy may be determined by computations based on various methods, or also by estimation as a function of certain parameters. Regardless of the way in which the first power requirement is determined, the second power requirement of the cooling circuit to be expected may also be determined by computations based on various methods, or by estimation as a function of certain parameters.
The method is used for reducing the overall power requirement of the motor vehicle. To this end, the temperature control system and the speed control system are coupled to one another, and may be regarded as a unit. Thus, in particular a slightly greater power requirement of the drive unit may be accepted when it is offset by a correspondingly lower second power requirement of the cooling circuit.
In addition, the method for optimizing the power requirement allows early, energy-efficient control of the temperature control system of the motor vehicle. Thus, in particular it may be recognized whether or not required temperature limits may be met despite predictive intervention, or only with significant energy consumption. The temperature control system is in bidirectional communication with the speed control system of the motor vehicle, so that in such cases the driving strategy of the motor vehicle may be adjusted. For example, the driving strategy is adjusted in such a way that a high heat input, which results in a high second power requirement of the cooling circuit, is reduced early. This may be achieved, for example, by appropriate control interventions in a transmission unit of the motor vehicle.
The driving strategy is preferably adjusted when an expected heat input for the drive unit exceeds a critical value.
The method for optimizing a power requirement is likewise suited for motor vehicles having an internal combustion engine, an electric motor, or a hybrid drive, and may also be combined with systems for heat recovery which supply further heat input to the cooling system.
Unnecessary control interventions in the cooling circuit are advantageously avoided, thus prolonging the service life of the corresponding components of the cooling circuit.
Mutually corresponding parts are provided with the same reference numerals in the FIGURE.